On Feb 18, 2006, at 3:01 PM, PL. Miraglia (home) wrote:
> consider the following:
>
> <rdfs:subClassOf>
> <owl:Restriction>
> <owl:onProperty rdf:resource="#R"/>
> <owl:someValuesFrom rdf:resource="#P"/>
> </owl:Restriction>
> <owl:Class rdf:about="#Q"/>
> </rdfs:subClassOf>
>
> I need some clarifications about this term: are these statements true
> or false?
>
> 1) The construct above is legal in OWL DL/Full not OWL Lite -- right?
FIrst I want to ask why do you care? It's relatively important to
distinguish between OWL Full and OWL DL, but much less so for OWL Lite
and OWL DL. Anyhoo.
This fragment alone (assuming a reasonable outer wrapping element) will
be owl full because of the lack of type triples for #R and #P (probably
objectproperty and class).
If the rest of the ontology is like that, I'll bet it is "repairable",
in which case, this fragment would be in OWL Lite, see:
http://www.w3.org/TR/owl-semantics/syntax.html#2.3.1
Pellet will suggest the extra type triples:
http://www.mindswap.org/2003/pellet/demo
Oh, and it's illegal RDF as it will have two object elements as the
value of one property element.
You may have meant something like this:
<owl:Class rdf:about="#A">
<rdfs:subClassOf>
<owl:Restriction>
<owl:onProperty rdf:resource="#R"/>
<owl:someValuesFrom rdf:resource="#P"/>
</owl:Restriction>
</rdfs:subClassOf>
<rdfs:subClassOf>
<owl:Class rdf:about="#Q"/>
</rdfs:subClassOf>
</owl:Class>
This is an implication (or two implications). In FOL:
(x)(Ax -> (some y)(Rxy & Py))
(x)(Ax -> Qx)
That's a pretty direct transliteration.
> (This is what the Wonderweb validator seems to indicate, although I
> found some of the OWL documents a bit unclear)
>
> 2) It is logically equivalent to the this FOL formula (KIFfy style):
>
> (implies
> (and (R x y) (P y))
> (Q x))
Er...don't think so. First off, your fragment above is incomplete.
Second, I take it that (Q x) is the consequent? See my translation
above.
> 3) Assuming that IR is the inverse of R, it is also logically
> equivalent to:
>
> <rdfs:subClassOf>
> <owl:Class rdf:about="#P"/>
> <owl:Restriction>
> <owl:onProperty rdf:resource="#R"/>
> <owl:allValuesFrom rdf:resource="#Q"/>
> </owl:Restriction>
> </rdfs:subClassOf>
I clearly don't understand what you are trying to do. Was Q supposed to
be the LHS of the subsumption?
Cheers,
Bijan.